Sanding machine



Dec. 13, 1960 a. J. VOELZ 2,963,831

SANDING MACHINE Filed Oct. 29, 1957 s Sheets-Sheet 1 INVEN TOR.

GORDON J. VOELZ zujm G. J. VOELZ SANDING MACHINE Dec. 13, 1960 3Sheets-Sheet 2 Filed Oct. 29, 1957 INVENTOR. GORDON J. VOELZ Dec. 13,1960 Filed Oct. 29, 1957 G. J. VOELZ SANDING MACHINE 3 Sheets-Sheet 3FIG-3 INVENTOR. GORDON J VOELZ xii 1m United States Patent O SANDINGMACHINE Gordon J. Voelz, New Haven, Conn., assignor to Olin MathresonChemical Corporation, a corporation of Virginia Filed Oct. 29, 1957,Ser. No. 693,101

2 Claims. (Cl. 51-142) The present invention relates to sanding machinesand in particular to machines operative to sand wooden work pieces suchas gun stocks. The invention also relates to a process practiced by theoperation of said machine. I

The invention is an improvement in the machine disclosed and describedin U.S. Patent 2,667,901, issued February 2, 1954, to Salstrom et a1.

In the present invention, there is contemplated a sanding machine havinga fixed frame for supporting a plurality of spindles in turn supportingwork pieces in the form of wooden blanks. The work pieces are spacedapart and are arranged in a generally parallel fashion.

The frame also supports a first carriage which is movable to and fro ina reciprocatory manner relative to the flame and relative to the workpieces along a path generally parallel to the axis about which the workpieces rotate. The first carriage supports a second carriage which isalso movable to and fro in a reciprocatory manner but along a path whichis perpendicular to the line of motion of the first carriage. The secondcarriage supports a belt sander which, by virtue of the mobility of thefirst and second carriages, is coordinately movable with respect to thework pieces effective to sand the work piece.

A master cam and follower is provided, usually an image of the surfacecontour to be sanded, effective to control motion of the second carriageand thus, the sander, along a path normal to the work pieces. A secondcam and follower means is provided for regulating the speed with whichthe sander traverses the work piece. A third cam and follower means isalso provided for regulating the speed with which the work piecesrevolve Accordingly, it is a particular feature of the present inventionto provide a sanding machine operable to sand wooden work pieces, suchas gun stocks, automatically.

It is a further object of the present invention to provide a sandingmachine including a belt sander movable coordinately under the controlof cams effective to sand a wooden element having an irregular surfacecontour including complex curves.

A further object of the invention is the provision of a sanding machineincluding a movably mounted belt sander operable to sand a plurality ofwork pieces simul taneously.

A sanding machine embracing certain principles of the present inventionmay comprise a main frame, a plurality of spindles mounted in the framefor receiving a corresponding number of work pieces, a first carriagemounted in the frame and movable to and fro along the longitudinal axisof the work pieces, a second carriage supported by the first carriageand movable relative to said first carriage along a path perpendicularto said longitudinal axis, a belt sander mounted upon the secondcarriage and operable by virtue of the motion of said first and secondcarriages to engage said work pieces, means for moving the firstcarriage relative to the frame and 2,963,831 Patented Dec. 13, 1960 formoving the second carriage relative to the first carriage effective tobring the sanding machine into contact with the work pieces and controlmeans including a master pattern for regulating the relative motion ofboth said carriages.

A process practiced by the operation of said machine may include thesteps of arranging a plurality of work pieces in at least two spacedtiers, disposing a belt sander between said spaced tiers of work pieces,rotating the work pieces slowly about their longitudinal axes and movingthe belt sander along a rectangular path between the tiers of workpieces and bringing the sander into contact alternately with one tier ofwork pieces and then with another to effect a continuous sandingoperation.

Other features and advantages of the present invention will become moreapparent from an examination of the succeeding specification when readin conjunction with the appended drawings in which:

Fig. 1 is a perspective view in schematic form of a portion of a machineembracing the principles of the present invention;

Fig. 2 is a plan view of the machine of Fig. 1 showing in greater detailthe improvement of the present invention; and,

Fig. 3is a vertical section of Fig. 2 as viewed in the plane of the line33.

In view of the fact that the present invention represents an improvementover the machine disclosed in said Salstrom patent, only those detailsthereof which are necessary to explain the present invention will bedescribed.

The main frame is composed of two vertical supports 10 and 11 tiedtogether by transverse tubular elements 12. A pair of horizontal bars 13and 14 span the vertical supports and carry a plurality of spindlesindicated generally by the reference numerals 16 and 17. The spindlessupport a corresponding number of work pieces indicated by the letter W.

A master cam indicated by the letter M and having followers 39 and 41 isalso supported by the bars 13 and 14. The master cam in cooperation withthe follower 39 controls sanding of the work pieces disposed to theright of the sanding element. (Fig. 1) while the master cam and follower41 control sanding of work pieces on the opposite side. A speed controlcam indicated by the letter S cooperates with a follower 19 forcontrolling the speed of advance of the sanding machine.Correspondingly, a speed control cam S1 having a follower 19--] iseffective to control the speed of motor P-2 and thus control therotational speed of the work pieces W, and the cams M and S.

A primary carriage 21 having rollers'22 is supported in the main frameby a pair of rods 23. The carriage is driven to and fro along the rodsand parallel to the axis of rotation of the work pieces by means of areversible motor indicated by the letter F through pinions 24-24 andracks 26-26 under the influence of speed control cam S and follower 19.

The primary carriage 21 in turn supports a secondary carriagecharacterizing a tubular frame indicated gen erally by the referencenumeral 27 wherein two pairs of rollers 28 and 29, respectively, carriedby the primary carriage are in rolling contact with tubular elements 31and 32 of the tubular frame. A double acting air cylinder 33 is utilizedfor actuating the tubular frame and for holding the belt sander incontact with the work pieces in a manner which will become more apparenthereinafter.

A pair of motors Pl-Pl are suitably mounted in the tubular frame and arefitted with pulleys 34 and 36 operative in cooperation with an idlerpulley 38 to drive an endless belt of sanding paper or cloth 37.

As is more apparent in Fig. 1, the belt 37 is led around idler pulley38. The pulley is pivotally mounted at its lower end so that its axis ofrotation may be moved to and fro through an arc in the direction of thearrow shown in Fig. 1 effective to keep the sanding, belt on the drivingpulleys 37 in awell known manner.

The reversible motor P is effective to move the primary carriage to andfro in a direction parallel to the longitudinal axes of the work piecesW While the air piston 33 is operative to move the tubular frame 27 in areciprocatory manner along a path generally perpendicular to thelongitudinal axes of the work pieces with the result that the beltsander follows a box-like path. indicated by the arrows of Fig. 1.

The secondary motor P2 is operative through suitable gearing to rotatethe work pieces W, the master cam M and speed control cams S and 8-1.

As stated previously, the tubular carriage is' provided with a pair offollowers 39 and 41 each engageable with the master cam on oppositesides thereof.

For example, the air' piston 33 is operative to drive the tubular frameto the left as viewed in Fig. 1 so that the follower 41 engages themaster cam thus controlling contact between the belt sander and the workpieces W tiered. to the left of the belt sander as the sander proceedsalong in the direction of the arrows. sander has traversed the fulllength of the work piece the hydraulic piston is operative to withdrawthe belt sander from a left hand group or tier of work pieces and ismoved into engagement with the work pieces on the opposite hand.correspondingly, cam follower 39 engages the opposite side of the mastercam to control the contact of the belt sander as it traverses the workpieces on the right side.

The belt sander continues to follow the box-like or rectangular pathuntil the work pieces have been rotated through 360" whereupon asuitable limit switch shuts down the machine.

Any number of belt sanding devices may be mounted in the tubular frame27 and there is no limit to the width of the belt sander necessary toaccommodate stacked or tiered work pieces as disclosed inFig. 1. Forexample, it is anticipated that an additional sander could be disposedin the area indicated generally by the reference numeral 42 and anynumber of work pieces may be tiered It is anticipated that a variety ofarrangements and dispositions of the sanding machine with respect towork pieces may be devised without departing from the spirit and scopeof the present invention.

What is claimed is:

1. An apparatus for sanding Work pieces, such asgun stocks, havingirregular surface contours including complex curves comprising a frame,a pair of movable carriages mounted in the frame, spindle means forrotatably supporting a plurality of spaced. groups of work piecescarried by the. frame, a beltsander mounted upon one of said carriagesand disposed between two groups of said work pieces, said carriagesbeing movable relative to one another and relative to'the frameeffective to bring the sander into contact with individual groups ofwork pieces sequentially and cam control means including a pair of camfollowers for regulating the motion of the belt sander in accordancewith a master pattern,

After the I p one follower being operative when said sander is incontact with a first group of said two groups of Work pieces and theother follower being operative when the sander is in contact with thesecond group of said two groups of work pieces whereby a sandingoperation is performed upon either the first or upon the second group ofwork pieces when the belt sander moves to and fro in a reciprocatoryfashion along a path generally parallel to the axis about which the workpieces rotate.

2. A method for sanding a plurality of wooden gun stocks automaticallyand in simultaneous fashion com prising the steps of arranging the workpieces in at least two spaced tiers, disposing a belt sander betweensaid tiers of work pieces, rotating the work pieces slowly about theirlongitudinal axes, moving the belt sander to and fro along a pathgenerally parallel to the longitudinal axis of the work pieces andbringing the sander into contact with a first tier of work pieces whilethe sander is moving in a first direction and bringing the sander intocontact with a second tier of work pieces when the sander is one abovethe other as consideration of convenience and operation during theentire duration of said reciprocatory stroke.

References Cited in the file of this patent UNITED STATES PATENTS624,882 Unkrich May 9, 1899 2,574,349 Otten Nov. 6, 1951 2,606,406Mueller Aug. 12, 1952 2,667,901 Salstrom et al. Feb. 2, 1954 2,722,787Hallewell et al. Nov. 8, 1955 2,727,338 Gronning Dec. 20, 1955 2,752,734McGibbon July 3, 1956 FOREIGN PATENTS 97,836 Sweden Ian. 16, 1940 n swas; M

